In the manufacturing of integrated circuits, sidewalls spacers are widely used for isolating certain features such as conductive features from other features. The sidewall spacers are vertical features whose vertical dimensions are greater than the respective horizontal dimensions. The formation of the sidewall spacers typically involves forming a blanket spacer layer, and performing an anisotropic etch to remove the horizontal portions of the blanket spacer layer. The remaining vertical portions are then left as the sidewall spacers.